#include <stdio.h>
int num2 = 20;
int main()//全局变量好像不能放在”main“和“{”之间；

 {
	extern int g_val;
	printf("%d\n", g_val);

	 {int  num1 = 10;
	 printf("%d\n", num1);
	
     printf("%d\n", sizeof(int));
	
     float f = 3.14;
	 printf("%f\n", f);
	
     short age = 18;
	 printf("%d\n", age);
	
     double weight = 95.6;
	 printf("%f\n", weight);
	
     int num = 2022;
	 char ch = 'A';
	 printf("%d\n", num);
	 printf("%c\n", ch);
	
     printf("zff\n");
	 
	 int num4 =0;
	 int num5= 0;
	 int sum = 0;
	 scanf_s("%d%d", &num4, &num5);
	 sum = num5 + num4;
	 printf("sum=%d\n", sum);
	 
	 }
	 printf("%d\n",num2);
	return 0;
}

